The greatly increased popularity of small boats has led to the establishment of numerous marinas for providing dock and mooring space therefor. Due to the limited shoreline space available, however, these marinas have become increasingly crowded with a corresponding difficulty of maneuvering the small boats entering and leaving the marina and docking in their individual mooring spaces. This calls for considerable skill and experience on the part of the boat owner in entering and leaving the marina, with the sole assistance of the conventional rudder and motor-driven propeller. Such skill and experience has often been lacking in boat operators, with the result that collisions have frequently occurred. The present invention provides an auxiliary hydraulic maneuvering system for small boats which greatly facilitates entering and leaving the marina and docking or undocking of the boat therein. When the operator has cleared the marina or is out of crowded or restricted waterways, he switches over to the conventional steering arrangement with which his boat is equipped, such as the rudder or steerable outboard engine.